The present invention relates to novel highly reactive polymer derivatives, articles such as biomedical articles, especially contact lenses, which are at least partly coated with said polymer derivatives and a process for coating inorganic or organic substrates using the novel polymer derivatives.
A variety of different types of processes for preparing polymeric coatings on a substrate have been disclosed in the prior art. For example, U.S. Pat. No. 5,527,925 describes functionalized photoinitiators and also organic substrates such as contact lenses containing said photoinitiators covalently bound to their surface. In one embodiment of said disclosure, the so modified surface of the contact lens is further coated with a photopolymerizable ethylenically unsaturated monomer which is then polymerized by irradiation thus forming a novel substrate surface. With this method, however, it is not always possible to obtain the desired coating characteristics, for example wettability characteristics which are necessary for the surface of biomedical devices including contact lenses. Most important, the known surface modification process is applicable only to articles having a functionalized surface, that is to say, the surface of the article either inherently contains functional groups or the functional groups have to be introduced previously by a plasma treatment or the like. However, it would be highly desirable to initiate the covalent binding of a hydrophilic layer on an xe2x80x9cinertxe2x80x9d surface and thereby avoiding a previous plasma treatment or the like.
Surprisingly, now there have been found novel reactive polymer derivatives which are able to react with the surface of articles that is devoid of functional groups. By means of said novel polymers it is possible to obtain articles, particularly biomedical devices such as, for example contact lenses, with an improved wettability, water-retention ability and biocompatibility.
The present invention therefore in one aspect relates to a compound of formula 
wherein R1 is an electron-withdrawing substituent and n is an integer from 0 to 2,
Z is a group which functions as a precursor for carbene or nitrene formation;
A is a radical of formula 
X and X1 are each independently of the other a group xe2x80x94Oxe2x80x94 or xe2x80x94NR2xe2x80x94, wherein R2 is hydrogen or C1-C4-alkyl;
A1 is C2-C30-alkyl which may be interrupted by xe2x80x94Oxe2x80x94;
R is linear or branched C1-C18-alkylene or unsubstituted or C1-C4-alkyl- or C1-C4-alkoxy-substituted C6-C10-arylene, C7-C18-aralkylene, C6-C10-arylene-C1-C2-alkylene-C6-C10-arylene, C3-C8-cycloalkylene, C3-C8-cycloalkylene-C1-C6-alkylene, C3-C8-cycloalkylene-C1-C2-alkylene-C3-C8-cycloalkylene or C1-C6-alkylene-C3-C8-cycloalkylene-C1-C6-alkylene; and
(oligomer) is
(i) the radical of a telomer of formula 
wherein (alk) is C2-C12-alkylene,
Q is a monovalent group that is suitable to act as a polymerization chain-reaction terminator,
p and q are each independently of another an integer from 0 to 750, wherein the total of (p+q) is an integer from 2 to 750,
and B and Bxe2x80x2 are each independently of the other a 1,2-ethylene radical derivable from a copolymerizable vinyl monomer by replacing the vinylic double bond by a single bond, at least one of the radicals B and Bxe2x80x2 being substituted by a hydrophilic substituent; or
(ixe2x80x94i) the radical of a telomer of formula 
wherein (alk*) Q*, p1 and q1 each independently have the meaning of (alk), Q, p and q,
B1 is a 1,2-ethylene radical derivable from a copolymerizable vinyl monomer by replacing the vinylic double bond by a single bond, which is substituted by a radical xe2x80x94T-(oligomer1),
wherein (oligomer1) independently is a radical of formula (3a) above and T is a direct bond or a radical of formula 
T1 is xe2x80x94Oxe2x80x94C2-C12-alkylene which is unsubstituted or substituted by hydroxy, or is
xe2x80x94Oxe2x80x94C2-C12-alkylene-NHxe2x80x94C(O)xe2x80x94 or xe2x80x94Oxe2x80x94C2-C12-alkylene-Oxe2x80x94C(O)xe2x80x94NHxe2x80x94R13xe2x80x94NHxe2x80x94C(O)xe2x80x94, wherein
R13 independently has the meaning of R above;
T2 is C1-C8-alkylene; phenylene or benzylene;
X3 and X4 are each independently of the other a bivalent group xe2x80x94Oxe2x80x94 or xe2x80x94NR2xe2x80x2, wherein R2xe2x80x2 is hydrogen or C1-C6-alkyl;
(alk**) is C1-C6-alkylene and (alk***) is C2-C12-alkylene, and
m and x are each independently of the other the number 0 or 1; and
B1xe2x80x2 independently has the meaning of B1 or B;
(ii) the radical of an oligomer of the formula 
wherein R3 is hydrogen or unsubstituted or hydroxy-substituted C1-C12-alkyl, u is an integer from 2 to 750 and Qxe2x80x2 is a radical of a polymerization initiator; or
(iii) the radical of formula 
wherein X2 independently has the meaning of X above, and R3 and u are as defined above, or
(iv) the radical of an oligomer of formula 
wherein R4 and R4xe2x80x2 are each independently C1-C4-alkyl, Anxe2x88x92 is an anion, v is an integer from 2 to 750, and Qxe2x80x3 is a monovalent group that is suitable to act as a polymerization chain-reaction terminator;
subject to the proviso that A is not a radical of formula (2b) if (oligomer) is a radical of formula (3b) or (3c).
The following preference apply to the variables contained in the definition of the compounds of formula (1):
Z is, for example, a group of formula 
wherein R5 is an electron-withdrawing substituent, for example, fluorinated C1-C6-alkyl, for example a radical xe2x80x94C2F5 or preferably a radical xe2x80x94CF3.
R1 is, for example, hydroxy, C1-C4-alkoxy, nitro, trifluoromethyl or halogen such as, for example, fluorine or chlorine.
The variable n is for example the number 1 or preferably 0.
X and X1 are each independently preferably a group xe2x80x94Oxe2x80x94 or xe2x80x94NHxe2x80x94 and in particular a group xe2x80x94NHxe2x80x94 each.
A1 is preferably linear C2-C12-alkyl radical witch may be interrupted by xe2x80x94Oxe2x80x94, for example a branched or preferably linear C2-C12-alkyl radical or in particular a radical xe2x80x94(CH2CH2O)1-5xe2x80x94CH2CH2xe2x80x94.
The radicals A of formulae (2a)-(2g) and the radicals of formulae (2a*)-(2e*) are in each case to be understood that the left bond is directed to the phenyl ring or B1 and the right bond is directed to (oligomer) or (oligomer1), respectively.
R as alkylene in formula (2g) is preferably linear or branched C1-C12-alkylene, more preferably C1-C6-alkylene and most preferably C1-C4-alkylene.
R as alkylene in formula (2f) is preferably a linear or branched C3-C14alkylene radical, more preferably a linear or branched C4-C12alkylene radical and most preferably a linear or branched C6-C10-alkylene radical.
When R is arylene, it is, for example, naphthylene or especially phenylene, each of which may be substituted, for example, by C1-C4-alkyl or by C1-C4-alkoxy. Preferably, R as arylene is 1,3- or 1,4-phenylene that is unsubstituted or substituted by C1-C4-alkyl or by C1-C4-alkoxy in the ortho-position to at least one linkage site.
R as aralkylene is preferably naphthylalkylene and most preferably phenylalkylene. The alkylene group in aralkylene contains preferably from 1 to 12, more preferably from 1 to 6 and most preferably from 1 to 4 carbon atoms. Most preferably, the alkylene group in aralkylene is methylene or ethylene.
When R is cycloalkylene, it is preferably C5-C6-cycloalkylene and most preferably cyclohexylene that is unsubstituted or substituted by methyl.
When R is cycloalkylene-alkylene, it is preferably cyclopentylene-C1-C4-alkylene and especially cyclohexylene-C1-C4-alkylene, each unsubstituted or mono- or poly-substituted by C1-C4-alkyl, especially methyl. More preferably, the group cycloalkylene-alkylene is cyclohexylene-ethylene and, most preferably, cyclohexylene-methylene, each unsubstituted or substituted in the cyclohexylene radical by from 1 to 3 methyl groups.
When R is alkylene-cycloalkylene-alkylene, it is preferably C1-C4-alkylene-cyclopentylene-C1-C4-alkylene and especially C1-C4-alkylene-cyclohexylene-C1-C4-alkylene, each unsubstituted or mono- or poly-substituted by C1-C4-alkyl, especially methyl. More preferably, the group alkylene-cycloalkylene-alkylene is ethylene-cyclohexylene-ethylene and, most preferably, is methylene-cyclohexylene-methylene, each unsubstituted or substituted in the cyclohexylene radical by from 1 to 3 methyl groups.
R as C3-C8-cycloalkylene-C1-C2-alkylene-C3-C8-cycloalkylene or C6-C10-arylene-C1-C2-alkylene-C6-C10-arylene is preferably C5-C6-cycloalkylene-methylene-C5-C6-cycloalkylene or phenylene-methylene-phenylene, each of which may be unsubstituted or substituted in the cycloalkyl or phenyl ring by one or more methyl groups.
The radical R in formula (2f) has a symmetrical or, preferably, an asymmetrical structure.
A preferred group of radicals A comprises those of formula (2f), wherein R is linear or branched C6-C10-alkylene; or cyclohexylene-methylene or cyclohexylene-methylene-cyclo-hexylene each unsubstituted or substituted in the cyclohexyl moiety by from 1 to 3 methyl groups.
The bivalent radical R in formula (2f) is derived preferably from a diisocyanate and most preferably from a diisocyanate selected from the group isophorone diisocyanate (IPDI), 4,4xe2x80x2-methylenebis(cyclohexyl isocyanate), 1,6-diisocyanato-2,2,4-trimethyl-n-hexane (TMDI), methylenebis(cyclohexyl-4-isocyanate) and hiexamethylene diisocyanate (HMDI).
In a further embodiment A is preferably a radical of formula (2a), (2b), (2d) or (2e), in particular (2a) or (2b).
One group of suitable compounds of formula (1) are those wherein Z is a group 
n is 0, and A is a radical of formula (2a).
A further group of suitable compounds of formula (1) are those wherein Z is a group xe2x80x94N3, n is 1 or preferably 0, and A is a radical of formula (2b), (2d) or (2e), in particular (2b).
The hydrophilic polymer (oligomer) has a number average molecular weight Mn of, for example, from 750 to 1000000 Da, preferably of from 1000 to 100000 Da, more preferably from 1500 to 75000 Da, even more preferably from 1500 to 50000 Da, and in particular from 2500 to 50000 Da.
If (oligomer) is a telomer radical (i), (alk) is preferably C2-C8-alkylene, more preferably C2-C6-alkylene, even more preferably C2-C4-alkylene and particularly preferably 1,2-ethylene. The alkylene radical (alk) may be a branched or preferably a linear alkylene radical.
Q may be any chain terminating fragment that is present in the reaction mixture during the preparation of the telomer, for example a hydrogen atom, a solvent radical, an initiator fragment or the radical of the chain transfer agent being used.
The total of (p+q) is preferably an integer from 10 to 750, more preferably from 15 to 700, even more preferably from 20 to 650 and particularly preferably from 40 to 600. In a preferred embodiment of the invention q is 0 and p is an integer from 2 to 750, preferably from 10 to 750, more preferably from 15 to 700, even more preferably from 20 to 650 and particularly preferably from 40 to 600. According to a further embodiment p and q are each independently from 1 to 749 and the total of (p+q) is preferably an integer from 10 to 750, more preferably from 15 to 700, even more preferably from 20 to 650 and particularly preferably from 40 to 600.
Suitable hydrophilic substituents of the radicals B or Bxe2x80x2 may be non-ionic, anionic, cationic or zwitterionic substituents. Accordingly, the telomer chain of formula (3a) that contains monomer units B and/or Bxe2x80x2 may be a charged chain containing anionic, cationic and/or zwitterionic groups or may be an uncharged chain. In addition, the telomer chain may comprise a copolymeric mixture of uncharged and charged units. The distribution of the charges within the telomer, if present, may be random or blockwise.
In one preferred embodiment of the invention, the telomer radical of formula (3a) is composed solely of non-ionic monomer units B and/or Bxe2x80x2. In another preferred embodiment of the invention, the telomer radical of formula (3a) is composed solely of ionic monomer units B and/or Bxe2x80x2, for example solely of cationic monomer units or solely of anionic monomer units. Still another preferred embodiment of the invention is directed to telomer radicals of formula (3a) comprising nonionic units B and ionic units Bxe2x80x2.
Suitable non-ionic substituents of B or Bxe2x80x2 include for example C1-C6-alkyl which is substituted by one or more same or different substituents selected from the group consisting of xe2x80x94OH, C1-C4-alkoxy and xe2x80x94NR6R6xe2x80x2, wherein R6 and R6xe2x80x2 are each independently of another hydrogen or unsubstituted or hydroxy-substituted C1-C6-alkyl or phenyl; phenyl which is substituted by hydroxy, C1-C4-alkoxy or xe2x80x94NR6R6xe2x80x2, wherein R6 and R6xe2x80x2 are as defined above; a radical xe2x80x94COOY, wherein Y is C1-C4-alkyl, C1-C24-alkyl which is substituted, for example, by hydroxy, C1-C4-alkoxy, xe2x80x94Oxe2x80x94Si(CH3)3, xe2x80x94NR6R6xe2x80x2 wherein R6 and R6xe2x80x2 are as defined above, a radical xe2x80x94Oxe2x80x94(CH2CH2O)1-24xe2x80x94E wherein E is hydrogen or C1-C6-alkyl, or a radical xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G, wherein xe2x80x94Oxe2x80x94G is the radical of a saccharide with 1 to 8 sugar units or is a radical xe2x80x94Oxe2x80x94(CH2CH2O)1-24xe2x80x94E, wherein E is as defined above, or Y is C5-C8-cycloalkyl which is unsubstituted or substituted by C1-C4-alkyl or C1-C4-alkoxy, or is unsubstituted or C1-C4-alkyl- or C1-C4-alkoxy-substituted phenyl or C7-C12-aralkyl; xe2x80x94CONY1Y2 wherein Y1 and Y2 are each independently hydrogen, C1-C4-alkyl, C1-C12-alkyl, which is substituted, for example by hydroxy, C1-C4-alkoxy or a radical xe2x80x94Oxe2x80x94(CH2CH2O)1-24xe2x80x94E wherein E is as defined above, or Y1 and Y2 together with the adjacent N-atom form a five- or six-membered heterocyclic ring having no additional heteroatom or one additional oxygen or nitrogen atom; a radical xe2x80x94OY3, wherein Y3 is hydrogen; C1-C4-alkyl or C1-C12-alkyl which is substituted by xe2x80x94NR6R6xe2x80x2; or is a radical xe2x80x94C(O)xe2x80x94C1-C4-alkyl; and wherein R6 and R6xe2x80x2 are as defined above; or a five- to seven-membered heterocyclic radical having at least one N-atom and being bound in each case via said nitrogen atom.
Suitable anionic substituents of B or Bxe2x80x2 include for example C1-C6-alkyl which is substituted by xe2x80x94SO3H, xe2x80x94OSO3H, xe2x80x94OPO3H2 and xe2x80x94COOH; phenyl which is substituted by one or more same or different substituents selected from the group consisting of xe2x80x94SO3H, xe2x80x94COOH, xe2x80x94OH and xe2x80x94CH2xe2x80x94SO3H; xe2x80x94COOH; a radical xe2x80x94COOY4, wherein Y4 is C1-C24-alkyl which is substituted for example by xe2x80x94COOH, xe2x80x94SO3H, xe2x80x94OSO3H, xe2x80x94OPO3H2 or by a radical xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94Gxe2x80x2 wherein Gxe2x80x2 is the radical of an anionic carbohydrate; a radical xe2x80x94CONY5Y6 wherein Y5 is C1-C24-alkyl which is substituted by xe2x80x94COOH, xe2x80x94SO3H, xe2x80x94OSO3H, or xe2x80x94OPO3H2 and Y6 independently has the meaning of Y5 or is hydrogen or C1-C12-alkyl; or xe2x80x94SO3H; or a salt thereof, for example a sodium, potassium, ammonium or the like salt thereof.
Suitable cationic substituents of B or Bxe2x80x2 include C1-C12-alkyl which is substituted by a radical xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92, wherein R6, R6xe2x80x2 and R6xe2x80x3 are each independently of another hydrogen or unsubstituted or hydroxy-substituted C1-C6-alkyl or phenyl, and Anxe2x88x92 is an anion; or a radical xe2x80x94C(O)OY7, wherein Y7 is C1-C24-alkyl which is substituted by xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92 and is further unsubstituted or substituted for example by hydroxy, wherein R6 R6xe2x80x2, R6xe2x80x3 and Anxe2x88x92 are as defined above.
Suitable zwitterionic substituents of B or Bxe2x80x2 include a radical xe2x80x94R7xe2x80x94Zw, wherein R7 is a direct bond or a functional group, for example a carbonyl, carbonate, amide, ester, dicarboanhydride, dicarboimide, urea or urethane group; and Zw is an aliphatic moiety comprising one anionic and one cationic group each.
The following preferences apply to the hydrophilic substituents of B and Bxe2x80x2:
(i) non-ionic substituents:
Preferred alkyl substituents of B or Bxe2x80x2 are C1-C4-alkyl, in particular C1-C2-alkyl, which is substituted by one or more substituents selected from the group consisting of xe2x80x94OH and xe2x80x94NR6R6xe2x80x2, wherein R6 and R6xe2x80x2 are each independently of another hydrogen or C1-C4-alkyl, preferably hydrogen, methyl or ethyl and particularly preferably hydrogen or methyl, for example xe2x80x94CH2xe2x80x94NH2, xe2x80x94CH2xe2x80x94N(CH3)2.
Preferred phenyl substituents of B or Bxe2x80x2 are phenyl which is substituted by xe2x80x94NH2 or N(C1-C2-alkyl)2, for example o-, m- or p-aminophenyl.
In case that the hydrophilic substituent of B or Bxe2x80x2 is a radical xe2x80x94COOY, Y as alkyl is preferably C1-C2-alkyl; Y as substituted alkyl is preferably C1-C12-alkyl, more preferably C1-C6-alkyl, even more preferably C1-C4-alkyl and particularly preferably C1-C2-alkyl, each of which being substituted as mentioned above. In case that the alkyl radical Y is substituted by xe2x80x94NR6R6xe2x80x2, the above-given meanings and preferences apply for R6 and R6xe2x80x2. Examples of suitable saccharide substituents xe2x80x94Oxe2x80x94G of the alkyl radical Y that is substituted by xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G are the radical of a mono- or disaccharide, for example glucose, acetyl glucose, methyl glucose, glucosamine, N-acetyl glucosamine, glucono lactone, mannose, galactose, galactosamine, N-acetyl galactosamine, fructose, maltose, lactose, fucose, saccharose or trehalose, the radical of an anhydrosaccharide such as levoglucosan, the radical of a glucosid such as octylglucosid, the radical of a sugar alcohol such as sorbitol, the radical of a sugar acid derivative such as lactobionic acid amide, or the radical of an oligosaccharide with a maximum of 20 sugar units, for example fragments of a cyclodextrin, a branched cyclodextrin, starch, chitosan, maltotriose or maltohexaose. The radical xe2x80x94Oxe2x80x94G preferably denotes the radical of a mono- or disaccharide or the radical of a cyclodextrin fragment with a maximum of 8 sugar units. Particular preferred saccharide radicals xe2x80x94Oxe2x80x94G are the radical of trehalose or the radical of a cyclodextrin fragment. In case that the alkyl radical Y is substituted by a radical xe2x80x94Oxe2x80x94(CH2CH2O)1-24xe2x80x94E or xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is xe2x80x94Oxe2x80x94(CH2CH2O)1-24xe2x80x94E, the number of (CH2CH2O) units is preferably from 1 to 12 in each case and more preferably from 2 to 8. E is preferably hydrogen or C1-C2-alkyl. Y as C5-C8-cycloalkyl is for example cyclopentyl or preferably cyclohexyl, each of which being unsubstituted or substituted for example by 1 to 3 C1-C2-alkyl groups. Y as C7-C12-aralkyl is for example benzyl.
Preferred nonionic radicals xe2x80x94COOY are those wherein Y is C1-C2-alkyl; or C2-C6-alkyl which is substituted by one or two substituents selected from the group consisting of hydroxy; C1-C2-alkoxy; xe2x80x94Oxe2x80x94Si(CH3)3; and xe2x80x94NR23R23xe2x80x2 wherein R23 and R23xe2x80x2 are each independently of another hydrogen or C1-C4-alkyl; or Y is a radical xe2x80x94CH2CH2xe2x80x94Oxe2x80x94(CH2CH2O)1-12xe2x80x94E wherein E is hydrogen or C1-C2-alkyl; or is a radical xe2x80x94C2-C4-alkylene-NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G, wherein xe2x80x94Oxe2x80x94G is the radical of a saccharide.
More preferred non-ionic radicals xe2x80x94COOY are those wherein Y is C1-C2-alkyl; or C2-C4-alkyl which is substituted by one or two substituents selected from the group consisting of xe2x80x94OH and xe2x80x94NR6R6xe2x80x2 wherein R6 and R6xe2x80x2 are each independently of another hydrogen or C1-C2-alkyl; or a radical xe2x80x94CH2CH2xe2x80x94Oxe2x80x94(CH2CH2O)1-12xe2x80x94E wherein E is hydrogen or C1-C2-alkyl; or is a radical xe2x80x94C2-C4-alkylene-NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is the radical of a saccharide.
Particularly preferred radicals xe2x80x94COOY comprise those wherein Y is C1-C2-alkyl, particularly methyl; or C2-C3-alkyl, which is unsubstituted or substituted by hydroxy or N,N-di-C1-C2-alkylamino, or is a radical -C2-C3-alkylenexe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is the radical of trehalose or the radical of a cyclodextrin fragment with a maximum of 8 sugar units.
Preferred non-ionic substituents xe2x80x94C(O)xe2x80x94NY1Y2 of B or Bxe2x80x2 are those wherein Y1 and Y2 are each independently of the other hydrogen, C1-C2-alkyl or C1-C6-alkyl which is substituted by hydroxy; or Y1 and Y2 together with the adjacent N-atom form a heterocyclic 6-membered ring having no further heteroatom or having one further N- or O-atom. Even more preferred meanings of Y1 and Y2, independently of each other, are hydrogen, C1-C2-alkyl or C1-C4-alkyl which is unsubstituted or substituted by hydroxy; or Y1 and Y2 together with the adjacent N-atom form a Nxe2x80x94C1-C2-alkylpiperazino or morpholino ring. Particularly preferred non-ionic radicals xe2x80x94C(O)xe2x80x94NY1Y2 are those wherein Y1 and Y2 are each independently of the other hydrogen, methyl or 2-hydroxyethyl; or Y1 and Y2 together with the adjacent N-atom form a morpholino ring.
Preferred non-ionic substituents xe2x80x94OY3 of B or Bxe2x80x2 are those wherein Y3 is hydrogen, C1-C2-alkyl, C1-C4-alkyl which is substituted by xe2x80x94NH2 or xe2x80x94N(C1-C2-alkyl)2, or is a group xe2x80x94C(O)C1-C2-alkyl. Y3 is particularly preferred hydrogen or acetyl.
Preferred non-ionic heterocyclic substituents of B or Bxe2x80x2 are a 5- or 6-membered heteroaromatic or heteroaliphatic radical having one N-atom and in addition no further heteroatom or an additional N- or O-heteroatom, or is a 5 to 7-membered lactame. Examples of such heterocyclic radicals are N-pyrrolidonyl, 2- or 4-pyridinyl, 2-methyl pyridin-5-yl, 2-, 3-oder 4-hydroxypyridinyl, N-xcex5-caprolactamyl, N-imidazolyl, 2-methylimidazol-1-yl, N-morpholinyl or 4-N-methylpiperazin-1-yl, particularly N-morpholinyl or N-pyrrolidonyl.
A group of preferred non-ionic substituents of B or Bxe2x80x2 comprises C1-C2-alkyl, which is unsubstituted or substituted by xe2x80x94OH or xe2x80x94NR6R6xe2x80x2, wherein R6 and R5xe2x80x2 are each independently of the other hydrogen or C1-C2-alkyl; a radical xe2x80x94COOY wherein Y is C1-C2-alkyl; C2-C4-alkyl which is substituted by xe2x80x94OH, xe2x80x94NR6R6xe2x80x2 wherein R6 and R6xe2x80x2 are each independently of another hydrogen or C1-C2-alkyl, or Y is a radical xe2x80x94C2-C4-alkylene-NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is the radical of a saccharide; a radical xe2x80x94C(O)xe2x80x94NY1Y2, wherein Y1 and Y2 are each independently of the other hydrogen, C1-C2-alkyl or C1-C6-alkyl which is unsubstituted or substituted by hydroxy, or Y1 and Y2 together with the adjacent N-atom form a heterocyclic 6-membered ring having no further heteroatom or having one further Nxe2x80x94or O-atom; a radical xe2x80x94OY3, wherein Y3 is hydrogen, C1-C2-alkyl, C1-C4-alkyl which is substituted by xe2x80x94NH2 or xe2x80x94N(C1-C2-alkyl)2, or is a group xe2x80x94C(O)C1-C2-alkyl; or a 5-or 6-membered heteroaromatic or heteroaliphatic radical having one N-atom and in addition no further heteroatom or an additional N-, O- or S-heteroatom, or a 5 to 7-membered lactame.
A group of more preferred non-ionic substituents of B or Bxe2x80x2 comprises a radical xe2x80x94COOY, wherein Y is C1-C2-alkyl, C2-C3-alkyl, which is substituted by hydroxy, amino or N,N-di-C1-C2-alkylamino, or is a radical xe2x80x94C2-C4-alkylene-NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is the radical of trehalose or a cyclodextrin fragment with a maximum of 8 sugar units; a radical xe2x80x94COxe2x80x94NY1Y2, wherein Y1 and Y2 are each independently of the other hydrogen, C1-C2-alkyl or C1-C4-alkyl which is substituted by hydroxy, or Y1 and Y2 together with the adjacent N-atom form a Nxe2x80x94C1-C2-alkylpiperazino or morpholino ring; or a heterocyclic radical selected from the group consisting of N-pyrrolidonyl, 2- or 4-pyridinyl, 2-methylpyridin-5-yl, 2-, 3-oder 4-hydroxypyridinyl, N-xcex5-caprolactamyl, N-imidazolyl, 2-methylimidazol-1-yl, N-morpholinyl and 4-N-methylpiperazin-1-yl.
A particularly preferred group of non-ionic substituents of B or Bxe2x80x2 comprises the radicals xe2x80x94COOxe2x80x94C1-C2-alkyl, xe2x80x94COOxe2x80x94(CH2)2-4xe2x80x94OH, xe2x80x94CONH2, xe2x80x94CON(CH3)2, xe2x80x94CONHxe2x80x94(CH2)2xe2x80x94OH, 
and xe2x80x94COO(CH2)2-4xe2x80x94NHC(O)xe2x80x94Oxe2x80x94G
wherein xe2x80x94Oxe2x80x94G is the radical of trehalose or a cyclodextrin fragment with a maximum of 8 sugar units.
(ii) anionic substituents:
Preferred anionic substituents of B or Bxe2x80x2 are C1-C4-alkyl, in particular C1-C2-alkyl, which is substituted by one or more substituents selected from the group consisting of xe2x80x94SO3H and xe2x80x94OPO3H2, for example xe2x80x94CH2xe2x80x94SO3H; phenyl which is substituted by xe2x80x94SO3H or sulfomethyl, for example o- , m- or p-sulfophenyl or o- , m- or p-sulfomethylphenyl; xe2x80x94COOH; a radical xe2x80x94COOY4, wherein Y4 is C2-C6-alkyl which is substituted by xe2x80x94COOH, xe2x80x94SO3H, xe2x80x94OSO3H, xe2x80x94OPO3H2, or by a radical xe2x80x94NHxe2x80x94C(O)xe2x80x94Oxe2x80x94Gxe2x80x2 wherein Gxe2x80x2 is the radical of lactobionic acid, hyaluronic acid, sialic acid or of a sialic acid terminated carbohydrate, for example sialidated galactose or lactobionic acid; in particular C2-C4-alkyl which is substituted by xe2x80x94SO3H or xe2x80x94OSO3H; a radical xe2x80x94CONY5Y6 wherein Y5 is C1-C6-alkyl substituted by sulfo, in particular C2-C4-alkyl substituted by sulfo, and Y6 is hydrogen, for example the radical xe2x80x94C(O)xe2x80x94NHxe2x80x94C(CH3)2xe2x80x94CH2xe2x80x94SO3H; or xe2x80x94SO3H; or a suitable salt thereof, for example the sodium or potassium salt or a biocompatible amine salt such as the triethanolamine salt. Particular preferred anionic substituents of B or Bxe2x80x2 are xe2x80x94COOH, xe2x80x94SO3H, o- , m- or p-sulfophenyl, o- , m- or p-sulfomethylphenyl or a radical xe2x80x94CONY5Y6 wherein Y5 is C2-C4-alkyl substituted by sulfo, and Y6 is hydrogen.
(iii) cationic substituents:
Preferred cationic substituents of B or Bxe2x80x2 are C1-C4-alkyl, in particular C1-C2-alkyl, which is in each case substituted by xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92; or a radical xe2x80x94C(O)OY7 wherein Y7 is C2-C6-alkyl, in particular C2-C4-alkyl, which is in each case substituted by xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92 and is further unsubstituted or substituted by hydroxy. R6, R6xe2x80x2 and R6xe2x80x3 are each independently of another preferably hydrogen or C1-C4-alkyl, more preferably methyl or ethyl and particularly preferably methyl. Examples of suitable anions Anxe2x88x92 are Halxe2x88x92, wherein Hal is halogen, for example Brxe2x88x92, F, Jxe2x88x92 or particularly Clxe2x88x92, furthermore HCO3xe2x88x92, CO32xe2x88x92, H2PO4xe2x88x92, HPO42xe2x88x92, PO43xe2x88x92, HSO4xe2x88x92, SO42xe2x88x92 or the radical of an organic acid such as OCOCH3xe2x88x92 and the like. A particularly preferred cationic substituent of B or Bxe2x80x2 is a radical xe2x80x94C(O)OY7 wherein Y7 is C2-C4-alkyl, which is substituted by xe2x80x94N(C1-C2-alkyl)3+Anxe2x88x92 and is further substituted by hydroxy, and Anxe2x88x92 is an anion, for example the radical xe2x80x94C(O)Oxe2x80x94CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94N(CH3)3+Anxe2x88x92.
(iv) zwitterionic substituents xe2x80x94R7xe2x80x94Zw:
R7 is a preferably a carbonyl, ester or amide functional group and more preferably an ester group xe2x80x94C(O)xe2x80x94Oxe2x80x94.
Suitable anionic groups of the moiety Zw are for example xe2x80x94COOxe2x88x92, xe2x80x94SO3xe2x88x92, xe2x80x94OSO3xe2x88x92, xe2x80x94OPO3Hxe2x88x92 or bivalent xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94 or xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94Oxe2x80x94, preferably a group xe2x80x94COOxe2x88x92 or xe2x80x94SO3xe2x88x92 or a bivalent group xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94, and in particular a group xe2x80x94SO3xe2x88x92.
Suitable cationic groups of the moiety Zw are for example a group xe2x80x94NR6R6xe2x80x2R6xe2x80x3+ or a bivalent group xe2x80x94NR6R6xe2x80x2+xe2x80x94, wherein R6, R6xe2x80x2 and R6xe2x80x3 are as defined above, and are each independently of the other, preferably hydrogen or C1-C6-alkyl, preferably hydrogen or C1-C4-alkyl and most preferably each methyl or ethyl.
The moiety Zw is for example C2-C30-alkyl, preferably C2-C12-alkyl, and more preferably C3-C8-alkyl, which is in each case uninterrupted or interrupted by xe2x80x94Oxe2x80x94, and substituted or interrupted by one of the above-mentioned anionic and cationic groups each, and, in addition, is further unsubstituted or substituted by a radical xe2x80x94OY8, wherein Y8 is hydrogen or the acyl radical of a carboxylic acid.
Y8 is preferably hydrogen or the acyl radical of a higher fatty acid.
A further embodiment relates to zwitterionic moieties wherein R7 is a group xe2x80x94C(O)NHxe2x80x94 and Zw is a radical of formula
xe2x80x94(CHR8xe2x80x94C(O)xe2x80x94NH)txe2x80x94CHR8xe2x80x94COOHxe2x80x83xe2x80x83(5),
wherein R8 is hydrogen or C1-C4-alkyl which is unsubstituted or substituted by hydroxy, carboxy, carbamoyl, amino, phenyl, o- ,m- or p-hydroxyphenyl, imidazolyl, indolyl or a radical xe2x80x94NHxe2x80x94C(xe2x95x90NH)xe2x80x94NH2 and t is an integer from 2 to 250, or Zw is the radical of an oligopeptide based on proline or hydroxyproline.
Zw is preferably C2-C12-alkyl and even more preferably C3-C8-alkyl which is substituted or interrupted by one of the above-mentioned anionic and cationic groups each, and in addition may be further substituted by a radical xe2x80x94OY8.
A preferred group of zwitter-ionic substituents xe2x80x94R7xe2x80x94Zw corresponds to the formula
xe2x80x94C(O)Oxe2x80x94(alkxe2x80x2xe2x80x3)xe2x80x94N(R6)2+xe2x80x94(alkxe2x80x2)xe2x80x94Anxe2x88x92 or
xe2x80x94C(O)Oxe2x80x94(alkxe2x80x3)xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94(O)0-1xe2x80x94(alkxe2x80x2xe2x80x3)xe2x80x94N(R6)3+
wherein R6 is hydrogen or C1-C6-alkyl; Anxe2x88x92 is an anionic group xe2x80x94COOxe2x88x92, xe2x80x94SO3xe2x88x92, xe2x80x94OSO3xe2x88x92 or xe2x80x94OPO3Hxe2x88x92, preferably xe2x80x94COOxe2x88x92 or xe2x80x94SO3xe2x88x92 and most preferably xe2x80x94SO3xe2x88x92, alkxe2x80x2 is C1-C12-alkylene, (alkxe2x80x3) is C2-C24-alkylene which is unsubstituted or substituted by a radical xe2x80x94OY8, Y8 is hydrogen or the acyl radical of a carboxylic acid, and (alkxe2x80x2xe2x80x3) is C2-C8-alkylene.
(alkxe2x80x2) is preferably C2-C8-alkylene, more preferably C2-C6-alkylene and most preferably C2-C4-alkylene. (alkxe2x80x3) is preferably C2-C12-alkylene, more preferably C2-C6-alkylene and particularly preferably C2-C3-alkylene which is in each case unsubstituted or substituted by hydroxy or by a radical xe2x80x94OY8. (alkxe2x80x2xe2x80x3) is preferably C2-C4-alkylene and more preferably C2-C3-alkylene. R9 is hydrogen or C1-C4-alkyl, more preferably methyl or ethyl and particularly preferably methyl. A preferred zwitterionic substituent of B or Bxe2x80x2 is of formula
xe2x80x94C(O)Oxe2x80x94CH2xe2x80x94CH(OY8)xe2x80x94CH2xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94(CH2)2xe2x80x94N(CH3)3+,
wherein Y8 is hydrogen or the acyl radical of a higher fatty acid.
B denotes for example a radical of formula 
wherein R9 is hydrogen or C1-C4-alkyl, preferably hydrogen or methyl; R10 is a hydrophilic substituent, wherein the above given meanings and preferences apply; R11 is C1-C4-alkyl, phenyl or a radical xe2x80x94C(O)OY9, wherein Y9 is hydrogen or unsubstituted or hydroxy-substituted C1-C4-alkyl; and R12 is a radical xe2x80x94C(O)Y9xe2x80x2 or xe2x80x94CH2xe2x80x94C(O)OY9xe2x80x2 wherein Y9xe2x80x2 independently has the meaning of Y9.
R11 is preferably C1-C2-alkyl, phenyl or a group xe2x80x94C(O)OY9. R12 is preferably a group xe2x80x94C(O)OY9xe2x80x2 or xe2x80x94CH2xe2x80x94C(O)OY9xe2x80x2 wherein Y9 and Y9xe2x80x2 are each independently of the other hydrogen, C1-C2-alkyl or hydroxy-C1-C2-alkyl. Particularly preferred xe2x80x94CHR11-CHR12xe2x80x94 units according to the invention are those wherein R11 is methyl or a group xe2x80x94C(O)OY9 and R12 is a group xe2x80x94C(O)OY9xe2x80x2 or xe2x80x94CH2xe2x80x94C(O)OY9xe2x80x2 wherein Y9 and Y9xe2x80x2 are each hydrogen, C1-C2-alkyl or hydroxy-C1-C2-alkyl.
Bxe2x80x2 independently may have one of the meanings given above for B.
If (oligomer) is a radical of formula (3a), the radical xe2x80x94(alk)xe2x80x94Sxe2x80x94[B]pxe2x80x94[Bxe2x80x2]qxe2x80x94Q preferably denotes a radical of formula 
even more preferably of the formula 
wherein for R9, R10, Q, p and q the above-given meanings and preferences apply, for R9xe2x80x2 independently the meanings and preferences given before for R9 apply, and for R10xe2x80x2 independently the meanings and preferences given before for R10 apply.
One embodiment of radicals (oligomer) concerns those radicals of formula (3axe2x80x2) or (3axe2x80x3), wherein R9 and R9xe2x80x2 are each independently hydrogen or methyl and R10 and R10xe2x80x2 are each independently one of the above-mentioned low molecular weight hydrophilic radicals, for example a radical having a weight average molecular weight of  less than 200; Suitable low-molecular weight radicals in this context are, for example, a non-ionic radical selected from the group of C1-C2-alkyl, which is unsubstituted or substituted by xe2x80x94OH or xe2x80x94NR6R6xe2x80x2, wherein R6 and R6xe2x80x2 are each independently of the other hydrogen or C1-C2-alkyl; a radical xe2x80x94COOY wherein Y is C1-C2-alkyl; C2-C4-alkyl which is substituted by xe2x80x94OH, xe2x80x94NR6R6xe2x80x2 wherein R6 and R6xe2x80x2 are each independently of another hydrogen or C1-C2-alkyl; a radical xe2x80x94C(O)xe2x80x94NY1Y2, wherein Y1 and Y2 are each independently of the other hydrogen, C1-C2-alkyl or C1-C6-alkyl which is unsubstituted or substituted by hydroxy, or Y1 and Y2 together with the adjacent N-atom form a heterocyclic 6-membered ring having no further heteroatom or having one further N- or O-atom; a radical xe2x80x94OY3, wherein Y3 is hydrogen, C1-C2-alkyl, C1-C4-alkyl which is substituted by xe2x80x94NH2 or xe2x80x94N(C1-C2-alkyl)2, or is a group xe2x80x94C(O)C1-C2-alkyl; and a 5- or 6-membered heteroaromatic or heteroaliphatic radical having one N-atom and in addition no further heteroatom or an additional N- , O- or S-heteroatom, or a 5 to 7-membered lactame; an anionic radical selected from xe2x80x94COOH, xe2x80x94SO3H, o- , m- or p-sulfophenyl, o- , m- or p-sulfomethylphenyl or a radical xe2x80x94CONY5Y6 wherein Y5 is C2-C4-alkyl substituted by sulfo, and Y6 is hydrogen; a cationic radical selected from C1-C4-alkyl, in particular C1-C2-alkyl, which is in each case substituted by xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92; or a radical xe2x80x94C(O)OY7 wherein Y7 is C2-C6-alkyl, in particular C2-C4-alkyl, which is in each case substituted by xe2x80x94NR6R6xe2x80x2R6xe2x80x3+Anxe2x88x92 and is further unsubstituted or substituted by hydroxy; or a zwitterionic radical selected from
xe2x80x94C(O)Oxe2x80x94(alkxe2x80x2xe2x80x3)xe2x80x94N(R6)2+xe2x80x94(alkxe2x80x2)xe2x80x94Anxe2x88x92 or
xe2x80x94C(O)Oxe2x80x94(alkxe2x80x3)xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94(O)0-1xe2x80x94(alkxe2x80x2xe2x80x3)xe2x80x94N(R6)3+
wherein R6 is hydrogen or C1-C2-alkyl; Anxe2x88x92 is an anionic group xe2x80x94COOxe2x88x92, xe2x80x94SO3xe2x88x92, xe2x80x94OSO3xe2x88x92 or xe2x80x94OPO3Hxe2x88x92, alkxe2x80x2 is C2-C4-alkylene, (alkxe2x80x3) is C2-C3-alkylene which is unsubstituted or substituted by hydroxy, and (alkxe2x80x2xe2x80x3) is C2-C4-alkylene.
A further embodiment of radicals (oligomer) concerns those radicals of formula (3axe2x80x2) or (3axe2x80x3), wherein R9 and R9xe2x80x2 are each independently hydrogen or methyl, at least one R10 is a radical comprising a hydrophilic side chain having a weight average molecular weight of xe2x89xa7200; and R10xe2x80x2 independently has the meaning of R10 or is a low molecular weight radical as mentioned above. R10 or R10xe2x80x2 as a radical comprising a hydrophilic side chain in this context are, for example a non-ionic substituent selected from the group consisting of a radical xe2x80x94COOY, wherein Y is a radical xe2x80x94CH2CH2xe2x80x94Oxe2x80x94(CH2CH2O)yxe2x80x94E, E is hydrogen or C1-C6-alkyl and y is an integer from 3 to 24, or Y is a radical xe2x80x94C2-C6-alkyl-NHxe2x80x94C(O)xe2x80x94Oxe2x80x94G wherein xe2x80x94Oxe2x80x94G is the radical of a saccharide or is a radical xe2x80x94Oxe2x80x94(CH2CH2O)yxe2x80x94E wherein E and y are each as defined above; and a radical xe2x80x94CONY1Y2, wherein Y1 is hydrogen or unsubstituted or, for example, hydroxy-substituted C1-C12-alkyl, and Y2 is C1-C12-alkyl which is substituted by a radical xe2x80x94Oxe2x80x94(CH2CH2O)yxe2x80x94E and wherein E and y are as defined above; and a zwitter-ionic substituent selected from a group of formula
xe2x80x94C(O)Oxe2x80x94CH2xe2x80x94CH(OY8)xe2x80x94CH2xe2x80x94Oxe2x80x94PO2xe2x88x92xe2x80x94(CH2)2xe2x80x94N(CH3)3+,
wherein Y8 is the acyl radical of a higher fatty acid, and a group of formula
xe2x80x83xe2x80x94C(O)NHxe2x80x94(CHR8xe2x80x94C(O)xe2x80x94NH)txe2x80x94CHR8xe2x80x94COOHxe2x80x83xe2x80x83(5),
wherein R8 is hydrogen or C1-C4-alkyl which is unsubstituted or substituted by hydroxy, carboxy, carbamoyl, amino, phenyl, o- , m- or p-hydroxyphenyl, imidazolyl, indolyl or a radical xe2x80x94NHxe2x80x94C(xe2x95x90NH)xe2x80x94NH2 and t is an integer from 2 to 250.
If (oligomer) is a radical (ixe2x80x94i) of formula (3axe2x80x94a), the following preferences apply for the variables contained therein:
For (alk*), Q*, p1 and q1 independently the preferences given above for (alk), Q, p and q apply. (oligomer1) is a radical of formula (3a) wherein the above-given meanings and preferences apply.
X3 is preferably a bivalent group xe2x80x94Oxe2x80x94 or xe2x80x94NHxe2x80x94, in particular xe2x80x94NHxe2x80x94. X4 is preferably xe2x80x94Oxe2x80x94 or xe2x80x94NHxe2x80x94.
For R13 independently the meanings and preferences given above for R in formula (2f) apply.
Preferred meanings of T1 are unsubstituted or hydroxy-substituted xe2x80x94Oxe2x80x94C2-C8-alkylene or a radical xe2x80x94Oxe2x80x94C2-C6-alkylene-NHxe2x80x94C(O)xe2x80x94 and particularly xe2x80x94Oxe2x80x94(CH2)2-4xe2x80x94, xe2x80x94Oxe2x80x94CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94 or a radical xe2x80x94Oxe2x80x94(CH2)2-4xe2x80x94NHxe2x80x94C(O)xe2x80x94. A particularly preferred meaning of T1 is the radical xe2x80x94Oxe2x80x94(CH2)2xe2x80x94NHxe2x80x94C(O)xe2x80x94. T2 is preferably C1-C6-alkylene, phenylene or benzylene, more preferably C1-C4-alkylene and even more preferably C1-C2-alkylene. x is an integer of 0 or preferably 1. m is preferably an integer of 1.
T is preferably a radical of formula (2b*) or in particular (2a*).
A preferred group of radicals B1 comprises radicals of the formula 
wherein R9 is hydrogen or C1-C4-alkyl, preferably hydrogen or methyl, and R10 is a radical xe2x80x94Txe2x80x94(oligomer1) wherein T is a radical of the formula (2a*) or (2b*) and (oligomer1) is a radical of formula (3a), where the above given meanings and preferences apply. An even more preferred group of radicals B1 comprises radicals of the above formula (6axe2x80x2), wherein R9 is hydrogen or methyl, and R10* is a radical xe2x80x94Txe2x80x94(oligomer1), wherein T is a radical of the formula (2a*) and (oligomer1) is a radical of formula (3a).
A preferred radical B1 is, for example a radical of formula 
where R9, R9xe2x80x2 and R9xe2x80x3 are each independently hydrogen or methyl, T1 is xe2x80x94Oxe2x80x94(CH2)2-4xe2x80x94, xe2x80x94Oxe2x80x94CH2xe2x80x94CH(OH)xe2x80x94CH2xe2x80x94 or a radical xe2x80x94Oxe2x80x94(CH2)2-4xe2x80x94NHxe2x80x94C(O)xe2x80x94, X3 is xe2x80x94Oxe2x80x94 or xe2x80x94NHxe2x80x94, (alk) is C2-C4-alkylene, Q is a monovalent group that is suitable to act as a polymerization chain-reaction terminator, and for R10, R10xe2x80x2, p and q each independently the above given meanings and preferences apply.
A particularly preferred radical B1 is of the formula 
wherein R9 and R9xe2x80x2 are each independently hydrogen or methyl, and for R10, Q, (alk) and p the above-given meanings and preferences apply. A particularly preferred group of radicals of the above formula (6axe2x80x2xe2x80x3) are those wherein R9 and R9xe2x80x2 are each independently hydrogen or methyl, (alk) is C2-C4-alkylene, p is an integer of 10 to 750, Q is as defined before, and for R10 the above given meanings and preferences apply; in particular R10 of this embodiment is a radical 
The radical B1xe2x80x2 is preferably independently a radical B wherein the above-given meanings and preferences apply. The variable q1 is most preferably 0 and for p1 independently the above-given meanings and preferences for p apply.
If (oligomer) is a radical (ii) of formula (3b), Qxe2x80x2 in formula (3b) is for example C1-C12-alkyl, phenyl or benzyl, preferably C1-C2-alkyl or benzyl and in particular methyl. R3 is preferably unsubstituted or hydroxy-substituted C1-C4-alkyl and in particular methyl. u is preferably an integer from 2 to 500, more preferably from 5 to 500, even more preferably from 5 to 250 and particularly preferably from 10 to 100.
If (oligomer) is a radical (iii) of formula (3bxe2x80x2), the above given meanings and preferences apply for the variables R3 and u contained therein. The radical X2H in formula (3bxe2x80x2) is preferably hydroxy or amino.
If (oligomer) denotes a radical (iv) of formula (3c), R4 and R4xe2x80x2 are each preferably ethyl or in particular methyl; v is preferably an integer from 2 to 500, more preferably from 5 to 500, even more preferably from 5 to 250 and particularly preferably from 10 to 100; Qxe2x80x3 is for example hydrogen; and An is as defined before.
Formulae (3a), (3axe2x80x94a), (3axe2x80x2) and (6axe2x80x3) are to be understood as a statistic description of the respective oligomeric radicals, that is to say, the orientation of the monomers and the sequence of the monomers (in case of copolymers) are not fixed in any way by said formulae. The arrangement of B and Bxe2x80x2 in formulae (3a), (3axe2x80x94a) or (3axe2x80x2) thus in each case may be random or blockwise.
The compounds of formula (1) may be prepared, for example, by reacting a compound of formula 
wherein A* is amino, Nxe2x80x94C1-C4-alkylamino, hydroxy, isocyanato, isothiocyanato, carboxy, or a carboxy derivative, for example an acid halide, ester or anhydride, and R1, Z and n are as defined above, with a compound of formula
A**xe2x80x94(oligomer)xe2x80x83xe2x80x83(8),
wherein (oligomer) is as defined above, and A** independently has the meaning of A* with the proviso that A** is coreactive to A*:
For example, the reactions of a compound of formula (7) having a carboxy, carboxylic acid halide group, ester, acid anhydride, isocyanato group or isothiocyanato group with an amino or hydroxy compound of formula (8), or vice versa, are well-known in the art and may be carried out as described in textbooks of organic chemistry. For example, the reaction of an isocyanato or isothiocyanato derivative of formula (7) with an amino- or hydroxy-compound of formula (8) may be carried out in an inert organic solvent such as an optionally halogenated hydrocarbon, for example petroleum ether, methylcyclohexane, toluene, chloroform, methylene chloride and the like, or an ether, for example diethyl ether, tetrahydrofurane, dioxane, or a more polar solvent such as DMSO, DMA, N-methyl-pyrrolidone or even a lower alcohol, at a temperature of from 0 to 100xc2x0 C., preferably from 0 to 50xc2x0 C. and particularly preferably at room temperature, optionally in the presence of a catalyst, for example a tertiary amine such as triethylamine or tri-n-butylamine, 1,4-diazabicyclooctane, or a tin compound such as dibutyltin dilaurate or tin dioctanoate. It is advantageous to carry out the above reactions under an inert atmosphere, for example under an nitrogen or argon atmosphere.
In case of a compound of formula (7) or (8) carrying a carboxy anhydride group, the reaction of the carboxy anhydride with a compound of formula (8) or (7) carrying an amino or hydroxy group may be carried out as described in organic textbooks, for example in an aprotic solvent, for example one of the above-mentioned aprotic solvents, at a temperature from room temperature to about 100xc2x0 C.
In case of a compound of formula (7) or (8) carrying a carboxy group, the reaction of the carboxy group with a compound of formula (8) or (7) carrying an amino or hydroxy group may be carried out under the conditions that are customary for ester or amide formation, for example in an aprotic medium at a temperature from about room temperature to about 100xc2x0 C. It is further preferred to carry out the esterification or amidation reaction in the presence of an activating agent, for example N-ethyl-Nxe2x80x2-(3-dimethylaminopropyl)carbodiimide (EDC), N-hydroxy succinimide (NHS) or N,Nxe2x80x2-dicyclohexyl carbodiimide (DCC).
The compounds of formula (1) may be isolated in a manner known per se and are advantageously purified before use, for example by precipitation with a suitable solvent, filtration and washing, extraction in a suitable solvent, dialysis, reverse osmoses (RO) or ultrafiltration, reverse osmoses and ultrafiltration being especially preferred.
The preferred purification processes for the copolymers of the invention, reverse osmoses and ultrafiltration, can be carried out in a manner known per se. It is possible for the ultrafiltration and reverse osmoses to be carried out repeatedly, for example from two to ten times. Alternatively, the ultrafiltration and reverse osmoses can be carried out continuously until the selected degree of purity is attained. The selected degree of purity can in principle be as high as desired.
The compounds of formula (7) are known and partly commercially available or may be prepared according to known processes. The compounds of formula (8) are likewise known, for example from WO 99/57581, or may be obtained according to processes known in the art.
A further object of the invention concerns a composite material comprising
(a) an inorganic or organic bulk material; and
(b) a hydrophilic surface coating obtainable by applying one or more different compounds of the formula (1) wherein for the variables contained therein the above given meanings and preferences apply, to the bulk material surface.
Examples of inorganic or organic bulk materials according to (a) are quartz, ceramics, glasses, silicate minerals, silica gels, metals, metal oxides, carbon materials such as graphite or glassy carbon, natural or synthetic organic polymers, or laminates, composites or blends of said materials, in particular natural or synthetic organic polymers which are known in large number. Some examples of polymers are polyaddition and polycondensation polymers (polyurethanes, epoxy resins, polyethers, polyesters, polyamides and polyimides); vinyl polymers (polyacrylates, polymethacrylates, polystyrene, polyethylene and halogenated derivatives thereof, polyvinyl acetate and polyacrylonitrile); or elastomers (silicones, polybutadiene and polyisoprene).
A preferred group of materials to be coated are those being conventionally used for the manufacture of biomedical devices, e.g. contact lenses, in particular contact lenses, which are not hydrophilic per se. Such materials are known to the skilled artisan and may comprise for example polysiloxanes, perfluoropolyethers, fluorinated poly(meth)acrylates or equivalent fluorinated polymers derived e.g. from other polymerizable carboxylic acids, polyalkyl (meth)acrylates or equivalent alkylester polymers derived from other polymerizable carboxylic acids, polyolefines, or fluorinated polyolefines, such as polyvinylidene fluoride, fluorinated ethylene propylene, or tetrafluoroethylene, preferably in combination with specific dioxols, such as perfluoro-2,2-dimethyl-1,3-dioxol. Examples of suitable bulk materials are e.g. Lotrafilcon A, Neofocon, Pasifocon, Telefocon, Silafocon, Fluorsilfocon, Paflufocon, Silafocon, Elastofilcon, Fluorofocon or Teflon AF materials, such as Teflon AF 1600 or Teflon AF 2400 which are copolymers of about 63 to 73 mol % of perfluoro-2,2-dimethyl-1,3-dioxol and about 37 to 27 mol % of tetrafluoroethylene, or of about 80 to 90 mol % of perfluoro-2,2-dimethyl-1,3-dioxol and about 20 to 10 mol % of tetrafluoroethylene.
Another group of preferred materials to be coated are amphiphilic segmented copolymers comprising at least one hydrophobic segment and at least one hydrophilic segment which are linked through a bond or a bridge member. Examples are silicone hydrogels, for example those disclosed in PCT applications WO 96/31792 and WO 97/49740.
The material to be coated may also be any blood-contacting material conventionally used for the manufacture of renal dialysis membranes, blood storage bags, pacemaker leads or vascular grafts. For example, the material to be modified on its surface may be a polyurethane, polydimethylsiloxane, polytetrafluoroethylene, polyvinylchloride, Dacron(trademark) or a composite made therefrom.
Moreover, the material to be coated may also be an inorganic or metallic base material with or without suitable reactive groups, e.g. ceramic, quartz, or metals, such as silicon or gold, or other polymeric or non-polymeric substrates. E.g. for implantable biomedical applications, ceramics or carbohydrate containing materials such as polysaccharides are very useful. In addition, e.g. for biosensor purposes, dextran coated base materials are expected to reduce nonspecific binding effects if the structure of the coating is well controlled. Biosensors may require polysaccharides on gold, quartz, or other non-polymeric substrates.
The form of the material to be coated may vary within wide limits. Examples are particles, granules, capsules, fibres, and particularly moldings of all kinds, for example tubes, films, membranes or biomedical moldings, in particular ophthalmic moldings, such as contact lenses, intraoccular lenses or artificial cornea. Further examples of moldings are materials useful for example as wound healing dressings, eye bandages, materials for the sustained release of an active compound such as a drug delivery patch, moldings that can be used in surgery, such as heart valves, vascular grafts, catheters, artificial organs, encapsulated biologic implants, e.g. pancreatic islets, materials for prostheses such as bone substitutes, or moldings for diagnostics, membranes or biomedical instruments or apparatus.
The compounds of formula (1) may be applied to the bulk material surface according to processes known per se. For example, the bulk material is immersed in a solution of a compound of formula (1), or a layer of a compound of formula (1) is first of all deposited on the modified bulk material surface, for example, by dipping, spraying, printing, spreading, pouring, rolling, spin coating or vacuum vapor deposition, dipping or especially spraying being preferred. Most preferably, a solution comprising one or more different compounds of the formula (1) is sprayed onto the bulk material surface which may be wet or preferably dry. According to a further preferred embodiment, the material to be coated is dipped in a solution of a compound of formula (1) in a solvent that is able to swell the material (swell-dipping).
Suitable solvents useful as solvents of the compounds of formula (1) are, for example, water, C1-C4-alkanols such as methanol, ethanol or iso-propanol, nitrites such as acetonitrile, tetrahydrofurane (THF), aqueous solutions comprising an alkanol, THF or the like, and also hydrocarbons, for example halogenated hydrocarbons such as methylene chloride or chloroform. The concentration of the compound of formula (1) in the spray solution depends on the specific compound used but is in general in the range of from 0.1 to 100 g/l, preferably 0.5 to 50 g/l, more preferably 0.5 to 25 g/l and in particular 1 to 10 g/l.
The fixation of the compounds of formula (1) on the bulk material surface then may be initiated , for example, by irradiation, particularly by irradiation with UV or visible light. Suitable light sources for the irradiation are known to the artisan and comprise for example mercury lamps, high pressure mercury lamps, xenon lamps, carbon arc lamps or sunlight. Sensitizers may be used to shift the irradiation wavelength. In addition, a suitable filter may be used to limit the irradiation to a specific wavelength range. Preferably, the bulk material surface to which have been previously applied the compound(s) of formula (1) is irradiated with light of a wavelength xe2x89xa7300 nm. The time period of irradiation is not critical but is usually in the range of up to 30 minutes, preferably from 10 seconds to 10 minutes, and more preferably from 15 seconds to 5 minutes, and particularly preferably from 20 seconds to 1 minute. It is advantageous to carry out the irradiation in an atmosphere of inert gas. After the polymerization, any non-covalently bonded polymers or non-reacted compound of formula (1) can be removed, for example by treatment, e.g. extraction, with suitable solvents, for example water, C1-C4-alkanols, water/C1-C4-alkanol mixtures or acetonitrile.
Depending on the desired properties and coating thickness the above outlined process cycle, (i) contacting, i.e. spraying or dipping, the surface with the compound(s) of formula (1) and (ii) fixing the compound(s) of formula (1) on the surface, i.e. by irradiation, may be carried out once or, preferably, several times. For example, 1 to 100, preferably 1 to 50 and in particular 5 to 25, different layers of one or more compounds of formula (1) are added and fixed on the bulk material surface. According to a further embodiment of the invention, the step (i) of contacting, i.e. spraying or dipping, the surface with the compound(s) of formula (1) is carried out several times, for example from 2 to 25 times and preferably from 2 to 10 times, and the fixation step (ii) is done only afterwards. If a process comprising several spraying or dipping steps is used, each spraying or dipping step may be carried out with the same polymer; alternatively different polymers may be used in each spraying or dipping step.
The thickness of the coating of the compound of formula (1) on the bulk material depends principally on the desired properties. It can be, for example, from 0.001 to 1000 xcexcm, preferably from 0.005 to 100 xcexcm, more preferably from 0.01 to 50 xcexcm, even more preferably from 0.01 to 5 xcexcm, especially preferably from 0.01 to 1 xcexcm and particularly preferably from 0.01 to 0.5 xcexcm.
The composite materials according to the invention and especially biomedical moldings comprising such a composite material have a variety of unexpected advantages over those of the prior art which make those moldings very suitable for practical purposes,e.g. as contact lens for extended wear or intraocular lens. For example, they do have a high surface wettability which can be demonstrated by their contact angles, their water retention and their water-film break up time or pre-lens or on-eye tear film break up time (TBUT).
The TBUT plays an particularly important role in the field of ophthalmic devices such as contact lenses. Thus the facile movement of an eyelid over a contact lens has proven important for the comfort of the wearer; this sliding motion is facilitated by the presence of a continuous layer of tear fluid on the contact lens, a layer which lubricates the tissue/lens interface. However, clinical tests have shown that currently available contact lenses partially dry out between blinks, thus increasing friction between eyelid and the lens. The increased friction results in soreness of the eyes and reduced movement of the contact lenses. Now it has become feasible to considerably increase the TBUT of commercial contact lenses such as, for example, Focus Dailies(trademark), Focus New Vues(copyright) or Lotrafilcon A lenses, by applying a surface coating according to the invention. On the base curve of a contact lens, the pronounced lubricity of the coating facilitates the on-eye lens movement which is essential for extended wear of contact lenses. Moreover, the composite materials of the invention provide additional effects being essential for lenses for extended wear, such as an increased thickness of the pre-lens tear film which contributes substantially to low microbial adhesion and resistance to deposit formation. Due to the extremely soft and lubricious character of the surface of the composite materials, biomedical articles such as in particular contact lenses show a superior wearing comfort including improvements with respect to late day dryness and long term (overnight) wear. The surface of the composite materials of the present invention moreover interact in a reversible manner with occular mucus which contributes to the improved wearing comfort.
In addition, biomedical devices, e.g. ophthalmic devices such as contact lenses, comprising a composite material according to the present invention, have a very pronounced biocompatibility combined with good mechanical properties. For example, the devices are blood compatible and have a good tissue integration. In addition, there are generally no adverse eye effects observed, while the adsorption of proteins or lipids is low, also the salt deposit formation is lower than with conventional contact lenses. Generally, there is low fouling, low microbial adhesion and low bioerosion while good mechanical properties can be for example found in a low friction coefficient and low abrasion properties. Moreover, the dimensional stability of the composite materials of the invention is excellent. In addition, the attachment of a hydrophilic surface coating at a given bulk material according to the invention does not affect its visual transparency.
In summary, the ophthalmic devices comprising a composite material according to the present invention, such as contact lenses, artificial cornea or intraocular lenses, provide a combination of low spoilation with respect to cell debris, cosmetics, dust or dirt, solvent vapors or chemicals, with a high comfort for the patient wearing such opthalmic devices in view of the soft hydrogel surface which for example provides a very good on-eye movement of the ophthalmic device.
Biomedical devices such as renal dialysis membranes, blood storage bags, pacemaker leads or vascular grafts comprising a composite material according to the present invention resist fouling by proteins by virtue of the continuous layer of bound water, thus reducing the rate and extent of thrombosis. Blood-contacting devices fabricated according to the present invention are therefore haemocompatible and biocompatible.
In the examples, if not indicated otherwise, amounts are amounts by weight, temperatures are given in degrees Celsius. Tear break-up time values in general relate to the pre-lens tear film non-invasive break-up time (PLTF-NIBUT) that is determined following the procedure published by M. Guillon et al., Ophthal. Physiol. Opt. 9, 355-359 (1989) or M. Guillon et al., Optometry and Vision Science 74, 273-279 (1997). Average advancing and receding water contact angles of coated and non-coated lenses are determined with the dynamic Wilhelmy method using a Krxc3xcss K-12 instrument (Krxc3xcss GmbH, Hamburg, Germany). Wetting force on the solid is measured as the solid is immersed in or withdrawn from a liquid of known surface tension.